We have developed an Outlook Add-in for Outlook Web App that requires users to log in via Office 365 (oauth2). However on Safari, the setting “Prevent cross-site tracking”, which is enabled by default, prevents 3rd party cookies, and therefore it is not possible to establish a user session (as the session id is managed via cookies).
If we disable the setting “Prevent cross-site tracking”, then it works fine, so it is clear that this is the issue.
What is the advice from Microsoft on how to enable sessions for Outlook Add-ins where 3rd party cookies are disabled (as is the case in Safari)?